Included here is the island of Java, one of the Great Sunda Islands Archipelago of Indonesia. Mountains extend along an east-west spine with over 30 mountain peaks. These have all been active volcanoes the highest of which is Mount Semeru (3676 m).

Javan Alpine Herbaceous Páramo

At altitudes of between 7000-8000 ft in a zone frequently enveloped by clouds there is a belt of tender herbs. It appears to be mainly confined to the gap between Mount Gedeh and Mount Pangerango, which is protected from strong winds and is consequently very moist. There are a few trees, but the tree ferns Dicksonia blumei and the endemic Cyathea cernuus (Cyatheaceae) occur, together with the grotesque liana Freycinetia, but it is the rich herbaceous undergrowth that characterizes this zone. The most common species is the pink flowered Impatiens platypetala, but others of this genus such as I. choneceras, I. cyclocoma and I. hirsuta are also encountered. Other common blossoms are Begonia isoptera and Ophiorrhiza longiflora. In places the tall succulent Strobilanthes cernuus forms dense thickets and nearly pure stands of Curculigo curvata occur. Other features include the sweet perfume smell of the ginger Hedychium coronarium.

Javan ‘Edelweiss’ Mountain Páramo

Above an altitude of about 9400 ft on Java’s Mount Gedeh and possibly in other upland sites is a sparse vegetation zone dominated by the small tree Albizzia montana and shrub Anaphalis javonica (Asteraceae). The latter with its grayish-white flowers is the edelweiss of Java. However, this species is not endemic to Java. It also occurs on Sulawesi and Sumatra. This alpine formation is mostly confined to the lava beds of Gedeh’s old crater, but it is regarded as a pioneer community appearing after other alpine vegetation is burned or otherwise destroyed.  Other characteristic species are the dwarf shrubs Gaultheria leucocarpa and Vaccinium varingiaefolium and the endemic tree-shrub Myrica javanica (Myricaceae). Surprisingly ferns, like the adaptable Polypodium feei, and lycopods such as the endemic Lycopodium gedeanum (Lycopodiaceae) are quite common. Other plants are few in number but where water becomes more plentiful small aquatic formation occur. Here the endemic sedge Gahnia javanica (Cyperaceae) can form huge scattered hillocks. 

Javan Alpine Vaccinium Subpáramo

Between altitudes ranging from about 8000-9000 ft on Java’s Mount Gedeh and Mount Pangerango is a zone largely dominated by species of Vaccinium. Five species occur: Vaccinium coriaceum, V. ellipticum, V. laurifolium, V. lucidum and V. varingiaefolium. This particular group of Vaccinium species has become remarkable polymorphic and can develop as trees, shrubs and lianas. Vaccinium varingiaefolium is particularly versatile having been recorded as a tree, shrub, liana and can grow both terrestrially and epiphytically. However, the trees at this elevation rarely grow to more than about 20 m in height and tend to have knarled, twisted trunks. A tree of some interest is Acer niveum, which can grow near to the summit of these mountains, is the only maple on Java. Other trees include Astronia spectabilis, Eury japonica, Polyosma ilicifolia and Rapanea avensis, although in some upper sections of this zone Vaccinium varingiaefolium occurs almost to the exclusion of other trees. Among the shrubs, Rododendron is a common colourful addition with the yellow flowers of R. cilium, red flowers of R. retusum and orange-red flowers of R. javanicum. Despite its name the latter species is not endemic to Java. Herb layer species include orchids such as Dendrobium hasseltii, the attractive Impatiens platypetala and the parasitic Balanophora elongata. The latter is curious plant with a short red flower-spike and parasitizes both Albizzia and Vaccinium. Other herb layer species are Viola serpens and the near endemic Ranunculus javanicus (Ranunculaceae). Epiphytes are numerous especially ferns of the genus Polypodium such as P. hirtellum, and there are many filmy ferns like the tiny Hymenophyllum paniculiflorum. Mosses are also abundant covering virtually every tree and vine.

References

Seifriz, W. 1923. The altitudinal distribution of plants on Mt Gedeh, Java. Bulletin of the Torrey Botanical Club, 50: 283-309.

Steenis, C. G. G. J. van. 1972. The mountain flora of Java. Leiden

Steenis, C. G. G. J. van. 1957. Outline of the vegetation types in Indonesia and some adjacent regions. Proceedings of the Pacific Scientific Congress, 8: 61-97.

Whitten, T., Soeriaatmadja, R. E. & Afiff, S. A. 1997. The Ecology of Java and Bali. Oxford University Press.